docs: def check_due(self):
          """Check if the last execution of this crawler is older than
          the scheduled interval."""
          if self.disabled:
              return False
          if self.is_running:
              return False
          if self.delta is None:
              return False
          last_run = self.last_run
          if last_run is None:
              return True
          now = datetime.utcnow()
          if now > last_run + self.delta:
              return True
          return False